YASKAWA T1000A Technical Manual page 19

DC Injection Braking
Motor overheat can result if there is too much current used during DC Injection Braking, or if the time for DC Injection
Braking is too long.
Acceleration/Deceleration Times
Acceleration and deceleration times are affected by how much torque the motor generates, the load torque, and the inertia
moment. Set a longer accel/decel time when Stall Prevention is enabled. The accel/decel times are lengthened for as long
as the Stall Prevention function is operating. For faster acceleration and deceleration, install one of the braking options
available or increase the capacity of the drive.
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General Handling
Wiring Check
Never connect the power supply lines to output terminals U/T1, V/T2, or W/T3. Doing so will destroy the drive. Be sure
to perform a final check of all sequence wiring and other connections before turning the power on. Make sure there are
no short circuits on the control terminals (+V, AC, etc.), as this could damage the drive.
Selecting a Circuit Breaker or Leakage Circuit Breaker
Yaskawa recommends installing equipment for residual current monitoring/detection (RCM/RCD) to the power supply
side. The RCM/RCD should be designed for use with an AC drive (e.g. Type B according to IEC 60755).
Select a MCCB (Molded Case Circuit Breaker) or RCM/RCD with a rated current that is 1.5 to 2 times higher than the
rated current of the drive in order to avoid nuisance trips caused by harmonics in the drive input current. Also refer to
Installing a Molded Case Circuit Breaker (MCCB) on page
Magnetic Contactor Installation
Use a magnetic contactor (MC) to ensure that power to the drive can be completely shut off when necessary. The MC
should be wired so that it opens when a fault output terminal is triggered.
Avoid switching a magnetic contactor on the power supply side more frequently than once every 30 minutes. Frequent
switching can cause damage to the drive.
Inspection and Maintenance
Capacitors in the drive take time to discharge even after the power has been shut off. After shutting off the power, wait
for at least the amount of time specified on the drive before touching any components.
The heatsink can become quite hot during operation, and proper precautions should be taken to prevent burns. When
replacing the cooling fan, shut off the power and wait at least 15 minutes to be sure that the heatsink has cooled down.
Even when the power has been shut off for a drive running a PM motor, voltage continues to be generated at the motor
terminals while the motor coasts to stop. Take the precautions described below to prevent shock and injury:
• In Applications where the machine can still rotate even though the drive has fully stopped a load switch for
disconnecting motor and drive should be installed to the output side of the drive.
• Do not allow an external force to rotate the motor beyond the maximum allowable speed, also when the drive has been
shut off.
• Wait for at least the time specified on the warning label after opening the load switch on the output side before
inspecting the drive or performing any maintenance.
• Do not open and close the load switch while the motor is running, as this can damage the drive.
• If the motor is coasting, make sure the power to the drive is turned on and the drive output has completely stopped
before closing the load switch.
Wiring
All wire ends should use ring terminals for UL/cUL compliance. Use only the tools recommended by the terminal
manufacturer for crimping.
Transporting the Drive
Never steam clean the drive.
During transport, keep the drive from coming into contact with salts, fluorine, bromine, phthalate ester, and other such
harmful chemicals.
YASKAWA ELECTRIC SIEP C710616 30B YASKAWA AC Drive T1000A Technical Manual
344.
i.2 General Safety
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